Polymer 80 Glock Build Project – Ghost Gun Range Day, Part-Three

UPDATE 8/20/2022: Laws regarding the ownership, serialization, and building of 80% firearms have changed. Please be sure and follow all state and federal laws.

Editors Note: Polymer 80 Glock Build Project: This article is part three in a three-part Ghost Gun series between The Truth About Guns, AmmoLand News, and USA Carry. Please visit our friends’ websites or use our navigation buttons to read parts one and two on this cool Polymer 80 Glock build.

Polymer 80 Glock Pistol Build now Complete #ghostgun
Polymer 80 Glock Pistol Build now Complete #ghostgun

USA –  -(AmmoLand.com)- Welcome to the final portion of our Polymer 80 Glock Build Project and part three of our joint collaboration between The Truth About Guns, AmmoLand News, and USA Carry. They should catch you up on our “spooky” ghost gun build. The Polymer 80 Pistol Project is our commentary on building one of these guns. We’ve covered what it is in part one, and the milling and assembling to be done with the design in part two. Now we are in the home stretch of our PF940C build.

Polymer 80 Glock Build – The Tight Slide

Polymer80 GLOCK : Get ready to cycle that slide.
Polymer80 GLOCK : Get ready to cycle that slide. You are going to be doing a lot of hand fitting.
Polymer 80 Glock Pistol Ghost Gun Build
Polymer 80 Glock Pistol Ghost Gun Build

A lot of builders, me included, often find our slides to be incredibly tight when they are first laid onto the frame. This is intentional as the slide has to fit the frame perfectly and needs to be run in by repeated slide cycling. This has occurred with both of my builds, and the solution was simple. Add lots of lube and start working on the slide. Make it go back and forth, over and over and over. Hundreds of times.

Slowly my build went from being so hard I had palm slap it to get it to go forward that eventually, I could gently push it forward to now where the slide will cycle manually just fine. It took a lot of cycling to get the slide moving. I would stop on occasion, add lube to the rails, and then start over. I also applied heat a few times and used gloves to manipulate the slide and frame.

It’s an annoying level of noise, but I suggest reading a book, watching a movie with headphones, or finding some other way to distract yourself.

Once it starts moving more and more freely, it becomes much more satisfying. You begin to see the whole kit come together and it is very satisfying. It is a mighty good feeling that the first time you rack the slide and have it cycle completely.

Polymer 80 Glock – To The Range!

Polymer 80 Glock Pistol Build First Shots
Polymer 80 Glock Pistol Build First Shots, You’ll reach certain milestones with live fire training. This includes the first time a spent round full ejects from the gun.

Shooting a brand new built Polymer 80 Glock going to be a little frustrating at first. Just like in the step above, we need to run the brand new pistol as one unit to get it broken in. The gun will not feed reliably, or possibly at all the first time you take it to the range. I do suggest loading up with quality brass ammo to help reduce problems caused by ammo quality. If you want to get some rock-solid malfunction training, this is the time to get it in.

Like the manual slide working, this takes time. You’ll reach certain milestones with live fire training. This includes the first time a spent round full ejects from the gun. Also, you’ll notice the slide running a little smoother and closing a little more. Along the way, I kept the gun quite well lubed.

Eventually, it will feed and eject, and you’ll be ecstatic. When it does, it is a mighty good feeling, but you’ll likely still encounter a problem or two for a little bit. Failures to feed is the main issue I met on my Polymer80 Pistol build and the main issue I seem to be encountering once every two or three magazines.

My break-in period isn’t exactly over, but I did fire approximately 150 rounds before it began to feed and eject with regularity. Most of it was Winchester White Box 115 grain, but a little 124 grain NATO spec loads were used to see if the little extra oomph would help. The first time the weapon fed reliably was with the 124 grain NATO spec loads. However, immediately after, it still fed 115-grain loads just as reliably.

One thing I did notice was the weapon worked better with Magpul and Amend 2 magazines. Glock OEM magazines gave more issues during the initial break-in period. Once the gun was feeding and ejecting regularly, they didn’t seem to be an issue.

Polymer 80 Glock – What’s Next?

Polymer80 Glock Pistol Ghost Gun Build Failure to Eject
Polymer80 Glock Pistol Ghost Gun Build Failure to Eject, Expect a lot of this as we break it in.

To get this so-called ghost gun gun running 100% (if there is such a thing), I plan to keep shooting it. That seems to be the best method to break it in. It’ll take time certainly, but in time I plan to start the joy of Glock upgrades to the kit.

I don’t trust myself to build a gun for defensive purposes just yet. Again an idiot-proof design tripped me up a bit so I need to practice a little more first. Since this isn’t a design for self-defense, I might go a bit goofy with it. Add a threaded barrel, a compensator, a flared magwell, do some nutty stuff overall to it for fun.

Polymer80 Builders Jig, remember where we started this ghost gun build?
Polymer80 Builders Jig, remember where we started this ghost gun build?
Polymer 80 Glock Pistol Build with Jig Finished #ghostgun
Polymer 80 Glock Pistol Build with Jig Finished #ghostgun

Building out my Polymer 80 Glock has been a lot of fun, it’s been challenging, and something I plan to do again. A G43 variant is likely my next build. 80-Lower.com also has SIG P320 build kits that look interesting, and I am most certainly interested in that too. Overall the Polymer 80 Glock build was a great project and left me with more respect for how reliable and perfect a true GLOCK pistol is right out the box. I highly recommend the readers take on this build, I guarantee it will not be your last.



Want to build your own Ghost Gun? Here are links to more Polymer80 parts, 80% lower gun kits and tools.

Travis Pike
Travis Pike

About Travis Pike

Travis Pike is a former Marine Machine Gunner, a lifelong firearms enthusiast, and now a regular guy who likes to shoot, write, and find ways to combine the two. He holds an NRA certification as a Basic Pistol Instructor and is the world’s Okayest firearm’s instructor.

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3 of our five Glocks are ‘ghosts’. Started with the 19/23 then the 26 and finally the 43. The 43 is the most sweet of them all. Never had any problems with FTE, FTF or any issues at all, actually. All the Glock and after market mags have worked well, except ets which I would never carry for defense anyway. They were fun to build but the worst part for a retired guy is that were so easy to build the process went too fast., LOL


I have built one in 9mm, with no issues that are described in this article. It went together easily and wasn’t tight and worked flawlessly the first time. Then I built a 40 S&W version. Same experience. Then I built a .357 SIG version, save experience again. I bought a .357 SIG barrel for the 40 and it works flawlessly that way too. And I’m going to be finishing a G22 size one with a .357 SIG barrel today. So to quote one of the posters below…IT IS ADDICTING!!! LOL! I have also been getting mine laser serialized in case… Read more »


Caution!!! Very addicting !!! I have built several of these and never had a tight slide as described, after about 5 slingshots and it felt like a real Glock. One step I do differently, I hand cut all of my plastic removal with end cutters and a sharp utility knife. If you shop around and buy the parts on sale or thanksgiving week, you can build one around $300-$325. Buying an $800 slide will not instantly make you a better shooter, practice will make you a better shooter. I also was looking at the Sig P320 build, but it is… Read more »

Green Mtn. Boy

JDT Agreed,the first one I did I had already seen MGB first couple of vids,so I did the tab removal much as you did and no problem encountered. The only things I used a Dremel for was drilling the holes and clean up of the tab of the recoil spring channel polishing after removal. The biggest mistake folks make is in drilling the pin holes with the poor quality M 3 and M 4 bits supplied in the kit. If one uses a Dremel #. 636 metric brad point set and the main problem with there use of that set… Read more »

Green Mtn. Boy

They are addictive and like Lays we’ll make more, They will cure the Ills of Gaston’s frames, he wasn’t willing to listen to what his customers didn’t care for because he created perfection .No more slippery grip textures, no more Glock hump,no more Glock knuckle,many ills to miss but not much to not like with the Poly 80 Polymer 80 did listen and gave folks what they wanted in the way of a frame and by doing so came much closer to perfection than Gaston ever did. At some point every Glock I own will have a frame much closer… Read more »


I agree, the P80 frame is pretty awesome!

Green Mtn. Boy


Now that you mention it,I have seriously considered their sale as they just take up room in the safe.

At some point I will take them to a friend who is a FFL and have him list them on gun broker,as they are not needed or wanted and would fund further frame replacements.


I’m wondering if valve grinding compound would make the initial break-in period shorter.

Green Mtn. Boy

Now having read part two,if he had read the instructions first, he would have drilled the pin holes first and then removed the tabs. It may have simplified his outcome and then perhaps not.

Polymer 80 instructions


Ej harbet

I bought a friends od 19 frame and just added my favorite parts and a swenson slide and barrel. Its the best 19 i ever owned! But i tried a g48 that .shoots slightly better.i guess the marksmen barrel is a real deal.